Despite the high prevalence, morbidity and mortality burden of chronic medical conditions among persons with Serious Mental Illness (SMI), few quality measurement protocols provide guidance on the optimal care of these complex patients. Guidelines have generally been developed for the simplest case-a person with only one disease-and it is not clear whether interventions are equally effective in complex populations with multiple medical and behavioral health co-morbidities, socio-economic disparities, or inequities in access to care. There remain substantial gaps in our knowledge about which interventions hold greatest promise for improving the overall health of populations with SMI and co-morbid medical disease; what system re- design will be most effective in delivering those interventions; or how treatments for mental illness (e.g. antipsychotics) may modify outcomes for medical conditions (e.g. diabetes). Maine has undertaken significant integrated care initiatives to improve physical and behavioral health outcomes for persons with SMI, including the state-wide implementation in 2013 of Medicaid Health Homes in mental health agencies (HHOPES) that will provide comprehensive care management and chronic disease self management support for consumers with diabetes. In addition to HHOPES implementation, Maine's mental health system is planning an antipsychotic quality improvement project designed to reduce the onset and burden of diabetes in the SMI population. This proposed NIMH project will take advantage of Maine's service delivery innovations to develop the research design and infrastructure necessary to support and evaluate the outcomes of these natural experiments. Products will include a person-specific dataset linked from multiple data sources; advances in the development of standardized metrics and procedures for analysis of Medicaid, Medicare, vital statistics, and clinical data; and process data on the challenges to implementing these models. In achieving these outcomes, this project will expand knowledge about best practices for improving health outcomes of persons with SMI.